1. Field of the Invention
The present invention relates to an image display apparatus using an electron-emitting device such as a field emission electron-emitting device or a surface conduction electron-emitting device and a light-emitting substrate used for the image display apparatus. More particularly, the present invention relates to a light-emitting substrate having a substrate on which an electrode to which a high potential is applied and an electrode to which a low potential is applied are arranged, at an interval. The present invention also relates to an information display and a reproduction apparatus using the light-emitting substrate, such as a television.
2. Related Background Art
Up to now, there have been attempts to produce an image display apparatus such as a so-called flat panel display. In such a display, a substrate including a large number of electron-emitting devices such as field emission electron-emitting devices or surface conduction electron-emitting devices is opposed to a light-emitting substrate including a phosphor such as a fluorescent material that emits light by irradiation with electrons emitted from the electron-emitting devices.
The light-emitting substrate composing the image display apparatus generally includes the phosphor such as the fluorescent material and an anode electrode that covers the phosphor (or which is located between the phosphor and a transparent insulating substrate), which are formed above the transparent insulating substrate. The anode electrode is composed of a thin electroconductive film. In particular, the anode electrode disposed on a surface of the phosphor facing (or opposed to) a substrate having the electron-emitting devices is called a “metal back”. Note that the function of the anode electrode is to accelerate electrons emitted from the electron-emitting devices and to irradiate the phosphor with the electrons passed through the anode electrode. In order to, for example, sharpen a displayed image, the light-emitting substrate further includes a light absorbing layer which is called a “black matrix”, a “black stripe” or the like in some cases. When the light-emitting substrate includes the light absorbing layer, the phosphor is located in an opening provided in the light absorbing layer.
When a high-resolution and high-luminance image is to be obtained on the above-mentioned flat panel display, it is preferable that an interval between the substrate on which the electron-emitting devices are arranged and the light-emitting substrate be held to 1 mm to 10 mm and a voltage of 10 kV to 30 kV be applied between both the substrates (typically, between the anode electrode and each of the electron-emitting devices).
When a high voltage is applied at such a narrow interval, for example, it is necessary to suppress the occurrence of undesirable discharge around the anode electrode. Therefore, there have been proposed that an electroconductive film to which a potential lower than a potential applied to the anode electrode is applied is located so as to surround the anode electrode (see JP 2001-250494 A, JP 2002-100313 A, JP 2002-150979 A, JP 2003-331760 A, and JP 10-097835 A).
Of those proposals, there is a proposal to locate a resistor film between the anode electrode and the electroconductive film in order to stabilize a voltage between the anode electrode and the electroconductive film located so as to surround the anode electrode.
There have been proposed the anode electrode is composed of a plurality of electroconductive films, for example, in order to suppress the occurrence of discharge between the anode electrode and each of the electron-emitting devices (see JP 2002-175764 A and JP 2003-229074 A).